For many years, chlorine has been used as a sanitizer in many types of bathing and recreational facilities such as swimming pools, spas, hot tubs and other similar facilities. Commonly, the chlorine is simply added to the water of such a facility in the form of a liquid, such as a solution of sodium hypochlorite, or in the form of a slow-dissolving solid so as to slowly release chlorine into the water over a period of time. More recently, chlorine is generated directly from the water of the facility itself wherein a quantity of salt is added to the water, with the water then subjected to an electrolysis process in order to obtain the chlorine. In order for this process to function efficiently, the salinity of the water in the bathing facility must be from about 2,000 parts per million to about 20,000 parts per million. Furthermore, during the electrolysis process, sodium hydroxide, a caustic alkaline compound, builds up in the water of the pool or other facility. While the sodium hydroxide may be controlled by addition of acids, such as hydrochloric acid, this forms other salts and undesirably adds to the chemical loading of the water. In other instances where hydrochloric acid is deemed too dangerous to handle, an acid salt may be added to the water, but this also adds to the chemical loading of the water. In both instances, any metals (except noble metals) exposed to the salt water are prone to corrosion from the salt. To overcome these problems, one manufacturer isolates the electrode that produces sodium hydroxide in a tank with a semipermeable membrane that passes electrons so that the sodium hydroxide is isolated from the pool water. However, the semipermeable membrane must be changed periodically, and the resulting sodium hydroxide treated and disposed. Another manufacturer utilizes a brine tank with the water therein being separate from the pool water. This is a relatively high maintenance system, requiring the brine to be changed fairly frequently, which involves neutralizing the sodium hydroxide therein before disposal. Both of the last two systems are also relatively expensive.
Accordingly, Applicant proposes to combine an ozone generator in conjunction with a chlorine generation system using salt in the water of the facility, the ozone reacting beneficially with the sodium hydroxide developed from the chlorine generation process. In addition, ozone is added to the water of the pool, greatly reducing chlorine requirements.